Precautions

It is very important that your doctor check the progress of you or your child at regular visits to make sure that this medicine is working properly. Blood tests will be needed to check for unwanted effects.

If your or your child's symptoms do not improve, or if they become worse, check with your doctor. You may need to take this medicine for several months before your infection gets better.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using the medicine, tell your doctor right away.

You or your child should not use astemizole (Hismanal®), barbiturates (such as phenobarbital or Luminal®), carbamazepine (Tegretol®), cisapride (Propulsid®), efavirenz (Sustiva®), ergot medicines (such as dihydroergotamine, ergotamine, Cafergot®, Ergomar®, or Wigraine®), pimozide (Orap®), quinidine (Quinaglute®), rifabutin (Mycobutin®), rifampin (Rifadin®, Rimactane®), ritonavir (Norvir®), sirolimus (Rapamune®), St. John's wort, or terfenadine (Seldane®). Using any of them together with this medicine may increase the chance of unwanted effects.

This medicine may cause vision problems. Avoid driving (especially at night), using machines, or doing anything else that could be dangerous if you cannot see well. Call your doctor if you or your child have any vision changes or if bright lights bother your eyes.

Check with your doctor right away if you or your child have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, unusual tiredness or weakness, or yellow eyes or skin. These could be symptoms of a serious liver problem.

Contact your doctor right away if you or your child have any changes to your heart rhythm. You might feel dizzy or faint, or you might have a fast, pounding, or uneven heartbeat. Make sure your doctor knows if you or anyone in your family has ever had a heart rhythm problem such as QT prolongation.

This medicine may make your skin more sensitive to sunlight. Use a sunscreen when you are outdoors. Avoid sunlamps and tanning beds.

Serious skin reactions can occur during treatment with this medicine. Check with your doctor right away if you or your child have blistering, peeling, loose skin, red skin lesions, severe acne or skin rash, sores or ulcers on the skin, or fever or chills while you are using this medicine.

This medicine may cause bone pain when used for a long period of time. Check with your doctor right away if you or your child have bone pain while using this medicine.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.